Tuptim Angkaew

Complete analysis of sideband instability in chain of periodic dispersion-managed fiber link and its effect on higher order dispersion-managed long-haul wavelength-division multiplexed systems

We present for the first time a complete theoretical analysis of sideband instability (SI) that occurs when two kinds of fibers with different characteristics are concatenated to form a dispersion-managed fiber link. In the analysis, the following three cases are taken into account: case (a) when a dispersion-management period is larger than an amplification period, case (b) when the two lengths are equivalent, and case (c) when a dispersion-management period is smaller than an amplification period. We find that the SI gain peak appears at frequencies determined by the larger of the two variation periods. Moreover, for all three cases, the magnitude of the SI gain reduces with the increase in strength of dispersion management. Next, we focus on the fiber link using the combination of standard single-mode fiber and reverse dispersion fiber, which is widely used for simultaneously compensating second- and third-order dispersion. By computer simulation, it is shown that in wavelength-division-multiplexed systems, SI still induces significant degradation in channels located at frequencies where SI induced from other channels arises. By reallocating the channel frequency to avoid the SI frequency, the transmission performance is improved significantly.

Simultaneous suppression of third-order dispersion and sideband instability in single-channel optical fiber transmission by midway optical phase conjugation employing higher order dispersion management

In optical phase conjugation (OPC) systems, the third-order dispersion (TOD) of optical fibers and the nonlinear resonance at well-defined signal sideband frequencies called sideband instability (SI) mainly limit the transmission performance. We propose, for the first time, a scheme for simultaneous suppression of both TOD and SI in OPC systems using a periodic higher order dispersion-managed link consisting of standard single-mode fibers (SMFs) and reverse dispersion fibers (RDFs). Computer simulation results demonstrate the possibility of 200-Gb/s data transmission over 10 000 km in the higher order dispersion-managed OPC system, where the dispersion map is optimized by our system design strategies.

Feasibility of 100-Gb/s 10000-km single-channel optical transmission by midway optical phase conjugation incorporated with third-order dispersion compensation

In optical phase conjugation systems, the third-order dispersion of fibers almost linearly accumulates along the transmission distance, and the distortion induced from the third-order dispersion can be perfectly compensated by using a linear third-order dispersion compensator placed at any point of the system. We demonstrate by numerical simulations that 100-Gb/s single-channel transmission can be achieved over a 10000-km distance in midway optical phase conjugation transmission systems by compensating the third-order dispersion.

Numerical Computation of Electromagnetic Far-field from Near-Field using Integral Equation based on Clifford Algebra

In this paper, it is proposed to compute the full far-field from the full near-field data by using integral equation based on Clifford algebras. This method can be used to solve directly the Maxwells equation based on Clifford algebras (Dirac equation) since the key tool is the fundamental solution of them. The formulation of this method is structured in the form Clifford arithmetic and the results appear in the form of Clifford numbers. However, the results are decoded into the electric and magnetic fields in order to compare directly with known analytical results.

Data rate penalty for high-density photonic integrated circuits in advanced modulation formats

We report on a simulation investigation of the effects of signal lines and core pitch on RF and optical crosstalk in integrated photonic circuits, and we discuss the data rate with photonic circuit density in advanced modulation formats such as 64QAM.

Crosstalk reduction for large scale photonic integrated circuits

The fundamental crosstalk characteristics related to design of highly compact optical and RF signal lines has been studied in this work. The systematic investigation of the crosstalk of parallel waveguides are carried out by modal analysis and the beam propagation analysis. The new idea of crosstalk mitigation in PIC by using uniform air gap along the longitudinal structure has been proposed. The crosstalk mitigation up to - 40dB by using air gap can successfully achieve, which results in reduction of spacing between signal lines.

Sideband instability in the presence of periodic power variation and periodic dispersion management

The analytical expression of sideband instability effect considering both periodic power variation and periodic dispersion management is derived. The result shows that the magnitude of sideband instability (SI) gain varies with the change of strength of dispersion management.

Applications of the modified extended ZY T-chart for problems associated with CCITLs with active characteristic impedances

The conjugately characteristic impedance transmission lines (CCITLs) implemented by lossless periodic transmission-line (TL) structures can exhibit active characteristic impedances (negative characteristic resistances). In this case, the magnitude of the voltage reflection coefficient is always greater than or equal to unity for passive load terminations. Due to complicated equations involved with terminated finite lossless periodic TL structures, the graphical tool called the modified extended ZY T-chart has been recently developed to assist in the analysis and design of these structures. This paper presents applications of the modified Tchart for problems associated with CCITLs with active characteristic impedances. In the determination of input impedances of terminated CCITLs, it is found that the modified T-chart yields sufficiently accurate results compared to those obtained from the extended ZY T-chart.

Time-Domain Finite-Element Beam Propagation Method with Generalized Polygonal Elements for Photonic Crystal Waveguides Analysis

In this paper, time-domain finite-element beam propagation method (TD-FE-BPM) using polygonal elements is presented for the analysis of 2D photonic crystal waveguides in order to reduce the unknown in system equations. The performance of the proposed method is compared with the TD-FE-BPM using all the triangular elements. The computation results of the pulse propagation along straight photonic crystal waveguide demonstrate the improvement in computation time by using the proposed method.